If there is a problem here, then it must be sorted. You cannot beat nature, and if the evidence is that a policy is not going to work, you should drop it, however great the headline that will thereby be lost. But I fear that this harsh message will not be fully accepted by ministers because they very often have to deal with human nature. The concern is with how people will respond to an educational programme, or to a change in benefit entitlements, or something like that. Human nature is known to be changeable, and ministers can then all too easily convince themselves that people will respond to new approaches or incentives in the ways that will make the policies succeed. Uncertainty about how people will respond leaves space for unwarranted optimism.

So what is the remedy? We have tried select committees, which are good but are easily ignored. When was a minister, or a senior civil servant, last sacked because a select committee found his or her policy-making skills wanting?

Here is my modest proposal. Any white paper that proposes new policies which rely for their success on people responding in certain ways must be written up with a full base of evidence, then the whole paper must be submitted to a couple of respected independent journals in the relevant field, which must each appoint a couple of reviewers who will go through the paper exactly as if they were peer-reviewing for publication in the journal. The reviewers' reports are then published.